Delivery sound masking and sound emission

ABSTRACT

An unmanned aerial vehicle (UAV) may emit masking sounds during operation of the UAV to mask other sounds generated by the UAV during operation. The UAV may be used to deliver items to a residence or other location associated with a customer. The UAV may emit sounds that mask the conventional sounds generated by the propellers and/or motors to cause the UAV to emit sounds that are pleasing to bystanders or do not annoy the bystanders. The UAV may emit sounds using speakers or other sound generating devices, such as fins, reeds, whistles, or other devices which may cause sound to be emitted from the UAV. Noise canceling algorithms may be used to cancel at least some of the conventional noise generated by operation of the UAV using inverted sounds, while additional sound may be emitted by the UAV, which may not be subject to noise cancellation.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of, and claims priority toco-pending, commonly owned, U.S. patent application Ser. No. 14/977,455filed Dec. 21, 2015 and entitled “Delivery Sound Masking And SoundEmission,” which is herein incorporated by reference in its entirety.

BACKGROUND

Use of unmanned aerial vehicles (UAVs) has become common by bothhobbyists and commercial entities. In the commercial context, UAVs havebeen used for photography, delivery of items, and for other reasons.During these uses, the UAVs may be exposed to people, who can often seeand hear the UAVs during operation. Once concern with the increase inpopularity of UAVs is the increase in noise from these devices, whichmay annoy the people exposed to operation of the UAVs.

An increase in noise may or may not influence people's perception of useof UAVs depending on the type of noise generated. For example, peoplewho live in an urban area are already surrounded by constant of noisefrom traffic, aircraft, sirens, and even neighbors. Some of these noisesare annoying while others seem to fade together and are easily ignored(e.g., traffic sounds, etc.).

BRIEF DESCRIPTION OF THE DRAWINGS

The detailed description is described with reference to the accompanyingfigures. In the figures, the left-most digit(s) of a reference numberidentifies the figure in which the reference number first appears. Thesame reference numbers in different figures indicate similar oridentical items.

FIG. 1 is a schematic diagram of an illustrative environment thatincludes an unmanned aerial vehicle (UAV) emitting masking sounds duringa delivery.

FIG. 2A is a block diagram of an illustrative UAV architecture.

FIG. 2B is a block diagram of an illustrative computing architecture ofa central command that exchanges communications with the UAV shown inFIG. 2A.

FIG. 3 is a perspective view of an illustrative propulsion system thatincludes one or more different sound masking devices.

FIG. 4 is a pictorial flow diagram of an illustrative process to emitdifferent sounds at different stages of flight by a UAV.

FIG. 5 is a flow diagram of an illustrative process to emitting maskingsounds during a delivery, some of the sounds possibly being selectedbased on information associated with a customer of the item(s) in thedelivery.

FIG. 6 is a flow diagram of an illustrative process to select customsounds for use during a delivery of a package by the UAV.

FIG. 7 is a flow diagram of an illustrative process to perform at leastpartial noise-canceling during operation of the UAV.

FIG. 8 is a flow diagram of an illustrative process to select sounds toemit based at least partly on attributes of a location of the UAV.

FIG. 9 is a flow diagram of an illustrative process to test sounds andreceive feedback from listeners enabling ranking of the sounds based onthe feedback.

DETAILED DESCRIPTION

This disclosure is directed to masking sound generated by an unmannedaerial vehicle (UAV) during operation. The UAV may be used to deliveritems to a residence or other location associated with a customer.During operation, the UAV may travel from a fulfillment center (FC),over or near populated areas of land, and to the destination. Duringtravel by a conventional UAV, the propellers (rotors) and/or motors maygenerate sounds, which may be annoying or otherwise displeasing tobystanders that hear that those sounds. As disclosed herein, the UAV mayemit sounds to mask the conventional sound generated by the propellersand/or motors to cause the UAV to emit sounds that are pleasing tobystanders or at least sounds that do not annoy the bystanders.

The UAV may emit sounds using speakers or other sound generatingdevices, such as fins, reeds, whistles, or other devices which may causesound to be emitted from the UAV. In some embodiments, sound generatingfeatures may be coupled to propellers, motors, and/or drive shafts thatcouple the propellers to respective motors. Noise canceling algorithmsmay be used to cancel at least some of the conventional noise generatedby operation of the UAV using inverted sounds, while additional soundmay be emitted by the UAV, which may not be subject to noisecancellation.

The UAV may emit different sounds based on a stage of flight and/orlocation of the UAV. For example, the UAV may emit a first sound duringtakeoff from the FC, a second sound during flight at a cruisingaltitude, a third sound during an approach to the destination, and afourth sound when the UAV is near or over the destination. In someembodiments, the UAV may dynamically select sounds to emit based on alocation of the UAV. For example, the UAV may emit different sounds whenlocated in an urban area than when the UAV is located in a rural orforested area. In the urban area, the UAV may emit sounds that blend inwith typical city noises (e.g., sounds of calmly moving traffic, muffledsounds, etc.), while in the rural area and/or forested area, the UAV mayemit sounds that blend in to those respective areas (e.g., sounds ofanimals and/or birds, sounds of wind, sounds of water, sounds ofmovement of trees, etc.).

In some embodiments, the sounds emitted by the UAV may be selected bythe customer or may be based on information about the customer. Forexample, the customer may be one of multiple people in a dwelling thatcan receive deliveries by a UAV. A particular customer may request theUAV to play a specific sound so that the customer can easily identifythe delivery as being for her and not one of the other people in thedwelling. In some embodiments, the sound may be selected for thecustomer based on information gathered about the customer, such asinformation about prior purchases using transaction history, profileinformation or customer account information, and/or other informationthat can readily be used to associate a sound with the customer that thecustomer may find agreeable and not annoying.

In various embodiments, the UAV may emit sounds near a destination,where the sounds are associated with a manufacturer of an item in thedelivery or other entity associated with the item. The UAV may emitspecial event sounds when approaching a destination or near thedestination. Special event sounds may include a birthday song, a songassociated with a sports team favored by the customer or associated withthe customer (e.g., alma mater song, etc.), a holiday song, or othersounds associated with special events. In some embodiments, listeners(bystanders) of the sounds emitted by the UAVs may provide feedback to aservice, which may use the feedback to select or rank sounds to be usedby the UAVs.

The techniques and systems described herein may be implemented in anumber of ways. Example implementations are provided below withreference to the following figures.

FIG. 1 is a schematic diagram of an illustrative environment 100 thatincludes a UAV emitting masking sounds during a delivery. Theenvironment 100 may include a fulfillment center (FC) 102 that deploysUAVs, such as a UAV 104 to deliver packages 106 to destinations, such asa destination 108 associated with a customer 110.

The UAV 104 may be configured to mask sound generated from operation ofthe UAV 104 during flight, such as conventional sound from rotation ofthe propellers and/or from the motors. The UAV 104 may use noisecancellation to cancel at least some of these conventional noises, andthereby may generate an inverted sound to cancel at least some of theconventional noises. The UAV 104 may emit different sounds 112(1), . . ., 112(N) during different stages of flight and/or at differentlocations, such as at locations 114(1), . . . 114(N) shown in FIG. 1.

For example, when the UAV 104 is at or traveling near a first location112(1) within a first threshold distance 116 from the FC 102 or fromanother departure location, the UAV may emit a first sound 112(1), suchas to announce or indicate departure from the FC 102. The UAV may emitthe sound as the UAV travels from the location, and thus is not limitedto only emitting the sounds at a particular location, but instead mayemit the sound during flight between locations.

The UAV 104 may progress to a second location 114(2) during flight,which may be a location at a cruising altitude. At or when travelingnear the second location 114(2), the UAV may emit a second sound 112(2).In some embodiments, the UAV may select the second sound based onattributes associated with the second location 114(2), such as thepresence of buildings 118, the presence of people 120, the presence ofwildlife 122, and/or other attributes. For example, when the secondlocation 114(2) is associated with the presence of building in an urbanarea, the UAV 104 may cause emission of the second sound 112(2) to“harmonize” or otherwise mimic urban sounds, for example. However, thesecond sound may be selected to including other types of sounds, such assounds from nature, animal or bird sounds, and/or other types of soundsas discussed below.

As the UAV 104 approaches the destination 108, the UAV 104 may enter asecond threshold distance 124 from the destination 108 and may be at ortraveling near a third location 114(3). When the UAV 104 is within thesecond threshold distance 124, but not yet within a third thresholddistance 126 from the destination 108, the UAV may emit a third sound112(3) during an approach to the destination 108. The third sound 112(3)may signify the approach of the UAV and may be selected as a sound thatis expected to be heard by the customer 110, if present at thedestination 108. For example, the third sound 112(3) may be anannouncement sound or song, a sound selected by the customer 110, anature sound, a soothing shy sound, a gentle animal sound, a soundassociated with a fictitious or real person, a cartoon character, or arobot, and/or other sounds that create a calming effect on listeners. Insome embodiments, the third sound 112(3) may be a special event sound(e.g., a sports themed sounds, a birthday song, etc.) or a soundassociated with a commercial entity associated with one of the items inthe package 106 (e.g., a theme song, an advertising jingle, etc.).

The UAV 104 may emit a fourth sound 112(4) when the UAV 104 is at ortraveling near a fourth location 114(4) within the third threshold 126from the destination, which may be during a deposit of the package 106at the destination 108. The fourth sound 112(4) may announce the depositof the item, warn bystanders of the UAV's presence, and/or provide otherinformation. The UAV 104 may then depart from the destination 108.

After depositing the package 106 at the destination 108, the UAV mayemit a fifth sound 112(5), such as during travel to/from a fifthlocation 114(5) at the cruising altitude. The fifth sound 112(5) may beselected in a similar way as the second sound 112(2). When the UAV 104returns within the first threshold distance 116 from the FA 102, such asat or near a sixth location 114(N), the UAV may emit a last sound112(N), such as to announce or indicate arrival at the FC.

In some embodiments, the sounds emitted by the UAV 104 may be selectedby a central command 128, which may control various operations of theUAV, including flight plans of the UAV and/or other high level decisionmaking. However, the UAV 104 may be configured to navigate at leastpartially using autonomous controls in case the UAV loses communicationwith the central command 128 and for other reasons. Thus, the UAV maydetermine flight plans in some embodiments. The central command 128 mayinterface with the customer 110, directly or indirectly, to select oneor more of the sounds 112(1)-(N) to be emitted by the UAV.

In various embodiments, the sounds selected for emission by the UAV 104may be themed as anthropomorphic sounds that personify the UAV to atleast some degree. For example, the UAV may emit sounds duringperformance of certain actions and may emit other sounds during atransition between actions. These sounds may create a character-likepersona and/or alert bystanders about actions performed by the UAV 104.In some instances, the UAV 104 may emit cartoon-like sounds, robotsounds, or other themed sounds that create a playful persona.

FIG. 2A is a block diagram of an illustrative UAV architecture 200 ofthe UAV 104. The UAV architecture 200 may be used to implement thevarious systems, devices, and techniques discussed above. In theillustrated implementation, the UAV architecture 200 includes one ormore processors 202, coupled to a non-transitory computer readable media220 via an input/output (I/O) interface 210. The UAV architecture 200may also include a propeller motor controller 204, power supply module206 and/or a navigation system 208. The UAV architecture 200 furtherincludes an inventory engagement mechanism controller 212, soundinput/output device(s) 214, a network interface 216, and one or moreinput/output devices 218.

In various implementations, the UAV architecture 200 may be implementedusing a uniprocessor system including one processor 202, or amultiprocessor system including several processors 202 (e.g., two, four,eight, or another suitable number). The processor(s) 202 may be anysuitable processor capable of executing instructions. For example, invarious implementations, the processor(s) 202 may be general-purpose orembedded processors implementing any of a variety of instruction setarchitectures (ISAs), such as the x86, PowerPC, SPARC, or MIPS ISAs, orany other suitable ISA. In multiprocessor systems, each processor(s) 202may commonly, but not necessarily, implement the same ISA.

The non-transitory computer readable media 220 may be configured tostore executable instructions/modules, data, flight paths, and/or dataitems accessible by the processor(s) 202. In various implementations,the non-transitory computer readable media 220 may be implemented usingany suitable memory technology, such as static random access memory(SRAM), synchronous dynamic RAM (SDRAM), nonvolatile/Flash-type memory,or any other type of memory. In the illustrated implementation, programinstructions and data implementing desired functions, such as thosedescribed above, are shown stored within the non-transitory computerreadable memory. In other implementations, program instructions, dataand/or flight paths may be received, sent or stored upon different typesof computer-accessible media, such as non-transitory media, or onsimilar media separate from the non-transitory computer readable media220 or the UAV architecture 200. Generally speaking, a non-transitory,computer readable memory may include storage media or memory media suchas flash memory (e.g., solid state memory), magnetic or optical media(e.g., disk) coupled to the UAV architecture 200 via the I/O interface210. Program instructions and data stored via a non-transitory computerreadable medium may be transmitted by transmission media or signals suchas electrical, electromagnetic, or digital signals, which may beconveyed via a communication medium such as a network and/or a wirelesslink, such as may be implemented via the network interface 216.

In one implementation, the I/O interface 210 may be configured tocoordinate I/O traffic between the processor(s) 202, the non-transitorycomputer readable media 220, and any peripheral devices, the networkinterface or other peripheral interfaces, such as input/output devices218. In some implementations, the I/O interface 210 may perform anynecessary protocol, timing or other data transformations to convert datasignals from one component (e.g., non-transitory computer readable media220) into a format suitable for use by another component (e.g.,processor(s) 202). In some implementations, the I/O interface 210 mayinclude support for devices attached through various types of peripheralbuses, such as a variant of the Peripheral Component Interconnect (PCI)bus standard or the Universal Serial Bus (USB) standard, for example. Insome implementations, the function of the I/O interface 210 may be splitinto two or more separate components, such as a north bridge and a southbridge, for example. Also, in some implementations, some or all of thefunctionality of the I/O interface 210, such as an interface to thenon-transitory computer readable media 220, may be incorporated directlyinto the processor(s) 202.

The propeller motor(s) controller 204 communicates with the navigationsystem 208 and adjusts the power of each propeller motor to guide theUAV along a determined flight path. The power supply module 206 maycontrol the charging and any switching functions associated with one ormore power modules (e.g., batteries) of the UAV.

The navigation system 208 may include a GPS or other similar system thatcan be used to navigate the UAV to and/or from a location. Thenavigation system may track a stage of flight of the UAV (e.g.,cruising, approach, takeoff, landing, etc.), an altitude, and/or aposition of the UAV relative to the destination. The inventoryengagement mechanism controller 212 communicates with the actuator(s) ormotor(s) (e.g., a servo motor) used to engage and/or disengageinventory. For example, when the UAV is positioned over a level surfaceat a delivery location, the inventory engagement mechanism controller212 may provide an instruction to a motor that controls the inventoryengagement mechanism to release the inventory.

The sound input/output device(s) 214 may include a microphone 214(1),including microphone arrays, speaker(s) 214(2), possibly including aspeaker array, and/or other sounds device(s) 214(M). The speaker(s)and/or sound devices 214(M) may be controlled by a sound devicecontroller 226 to cause the UAV to emit one or more sounds, such as asound that masks at least some sound generated by the propellers and/ormotors of the UAV 104. Illustrative sound devices 214(M) are shown anddescribed with reference to FIG. 3. The microphone 214(1) may be used bya noise canceling module 222 in coordination with the speaker(s) 214(2)to cancel at least some of the sound generated by the propellers and/ormotors of the UAV 104. The speaker(s) 214(2) may be controlled atdifferent times to emit sounds to mask the sounds of the UAV, to mimicenvironmental sounds, and/or to emit other noises that calm, sooth,reassure, and/or avoid annoying bystanders.

The network interface 216 may be configured to allow data to beexchanged between the UAV architecture 200, other devices attached to anetwork, such as other computer systems (e.g., the central command 128,etc.), and/or with UAV control systems of other UAVs. For example, thenetwork interface 216 may enable wireless communication between numerousUAVs. In various implementations, the network interface 216 may supportcommunication via wireless general data networks, such as a Wi-Finetwork. For example, the network interface 216 may supportcommunication via telecommunications networks such as cellularcommunication networks, satellite networks, and the like.

Input/output devices 218 may, in some implementations, include imagecapture devices, infrared sensors, time of flight sensors,accelerometers, lights, speakers, and other input/output devicescommonly used in aviation. Multiple input/output devices 218 may bepresent and controlled by the UAV architecture 200. One or more of thesesensors may be utilized to assist in landings as well as avoidingobstacles during flight.

In some embodiments, the computer readable media 220 may store the noisecanceling module 222, a sound selection module 224, the sound devicecontroller 226, and a location module 228, which are described in turn.The components may be stored together or in a distributed arrangement.The computer readable memory may also store data 230, such as sounds,location information used to select sounds, and/or other data usable bythe various modules.

The noise canceling module 222 may employ sound cancellation algorithmsthat receive a sound signal input from the microphone 214(1), createinverted sound signals that cancel at least part of the sound generatedby the UAV, and cause the speaker(s) to emit sound based on the invertedsound signals. In various embodiments, the noise canceling module 222may cancel or target for cancellation “annoying” portions of soundgenerated by the UAV, such as to cancel some, but not all of the soundsemitted by the UAV.

The sound selection module 224 may select sounds to be emitted by theUAV, such as by the speaker(s) 214(2) and/or by the sound devices214(M). The sound selection module 224 may access sounds from the data230, such as prerecorded sounds, jingles, and/or other sounds foremission by the UAV. In some embodiments, the sound selection module 224may select sounds based on attributes of an environment (e.g., populatedareas, urban area, forested area, rural area, etc.), distance from adeployment location, distance from a destination, stage of flight,and/or other factors.

The sound device controller 226 may control emission of sound by thespeaker(s) 214(2) and/or by the sound devices 214(M) to cause thedevices to emit sound selected by the sound selection module 224. Thesound device controller 226 may manipulate the sound devices 214(M) tocause the sound devices to make different sounds and/or cease makingsounds, such as when the sound devices 214(M) include whistles, reeds,and/or other devices that generate noise based on airflow across orthrough a component.

The location analysis module 228 may determine attributes about alocation, such as an environment that the UAV 104 is currently within,to inform the sound selection module 224 about sounds that may beappropriate for that location/environment. For example, the locationanalysis module 228 may detect presence of buildings and urban areafeatures, which may direct the sound selection module 224 to select afirst set of sounds for emission by the UAV 104. As another example, thelocation analysis module 228 may detect presence of animals, farms, andother rural features, which may direct the sound selection module 224 toselect a second set of sounds for emission by the UAV 104.

Additional operation of the various modules discussed above is providedwith reference to the various flow diagrams below described withreference to FIGS. 4-9.

In various implementations, the parameter values and other dataillustrated herein as being included in one or more data stores may becombined with other information not described or may be partitioneddifferently into more, fewer, or different data structures. In someimplementations, data stores may be physically located in one memory ormay be distributed among two or more memories.

Those skilled in the art will appreciate that the UAV architecture 200is merely illustrative and is not intended to limit the scope of thepresent disclosure. In particular, the computing system and devices mayinclude any combination of hardware or software that can perform theindicated functions, including computers, network devices, internetappliances, PDAs, wireless phones, pagers, etc. The UAV architecture 200may also be connected to other devices that are not illustrated, orinstead may operate as a stand-alone system. In addition, thefunctionality provided by the illustrated components may in someimplementations be combined in fewer components or distributed inadditional components. Similarly, in some implementations, thefunctionality of some of the illustrated components may not be providedand/or other additional functionality may be available.

Those skilled in the art will also appreciate that, while various itemsare illustrated as being stored in memory or storage while being used,these items or portions of them may be transferred between memory andother storage devices for purposes of memory management and dataintegrity. Alternatively, in other implementations, some or all of thesoftware components may execute in memory on another device andcommunicate with the illustrated UAV architecture 200. Some or all ofthe system components or data structures may also be stored (e.g., asinstructions or structured data) on a non-transitory,computer-accessible medium or a portable article to be read by anappropriate drive, various examples of which are described above. Insome implementations, instructions stored on a computer-accessiblemedium separate from the UAV architecture 200 may be transmitted to theUAV architecture 200 via transmission media or signals such aselectrical, electromagnetic, or digital signals, conveyed via acommunication medium such as a wireless link. Various implementationsmay further include receiving, sending or storing instructions and/ordata implemented in accordance with the foregoing description upon acomputer-accessible medium. Accordingly, the techniques described hereinmay be practiced with other UAV control system configurations.

Additional information about the operations of the modules of the UAV104 is discussed below with reference to the flow diagrams.

FIG. 2B is a block diagram of an illustrative computing architecture 240of the central command 110 that exchanges communications with the UAV104. The computing architecture 240 may include one or more processors242 and one or more computer readable media 244 that stores variousmodules, applications, programs, or other data. The computer-readablemedia 244 may include instructions that, when executed by the one ormore processors 242, cause the processors to perform the operationsdescribed herein for the central command 110. The architecture 240 mayalso include network communication devices 246 to facilitatecommunication with other devices, such as using wired and/or wirelessnetworks.

Embodiments may be provided as one or more a computer programs includinga non-transitory machine-readable storage medium having stored thereoninstructions (in compressed or uncompressed form) that may be used toprogram a computer (or other electronic device) to perform processes ormethods described herein. The machine-readable storage medium mayinclude, but is not limited to, hard drives, floppy diskettes, opticaldisks, CD-ROMs, DVDs, read-only memories (ROMs), random access memories(RAMs), EPROMs, EEPROMs, flash memory, magnetic or optical cards,solid-state memory devices, or other types of media/machine-readablemedium suitable for storing electronic instructions. Further,embodiments may also be provided as a computer program product includinga transitory machine-readable signal (in compressed or uncompressedform). Examples of machine-readable signals, whether modulated using acarrier or not, include, but are not limited to, signals that a computersystem or machine hosting or running a computer program can beconfigured to access, including signals downloaded through the Internetor other networks.

In some embodiments, the computer-readable media 204 may store acustomer preference module 248, a special events module 250, anorder-specific sounds module 252, and a sound assignment module 254,which are described in turn. The components may be stored together or ina distributed arrangement. The computer-readable media 242 may alsoinclude data 256. The data 256 may include a customer profile data,sounds, special events, and/or other data used by the various modulesdiscussed herein.

The customer preference module 248 may enable a customer to specifysounds to be emitted by the UAV at one or more stages of the flight ofthe UAV. In some embodiments, the customer preference module 248 mayreceive a selection of a sound, song, and/or other audible noise to beassociated with the customer. The sound may then be emitted by the UAV104, such as during the approach (e.g., as the third sounds 112(3)described above with reference to FIG. 1) and/or during the deposit of apackage (e.g., as the forth sound 112(4) described above with referenceto FIG. 1). The customer preference module 248 may restrict selection torefrain from causing the UAV to emit sounds deemed annoying, offensive,or otherwise disliked by a threshold number or percentage of bystanders.

In some embodiments, the customer preference module 248 may select asound for the customer based on information associated with thecustomer. For example, the customer preference module 248 may selectsounds based on prior purchases by the customer, information in acustomer's profile or account, information posted by the customer in asocial network site, and/or other information. For example, the customerpreference module 248 may determine a customer's alma mater, and mayselect a school song for the alma mater to play for the customer. Asanother example, the customer preference module 248 may determine thatthe customer likes classical music based on prior purchase or selectionsby the customer, and thus may cause the UAV to play classical music orsounds that resemble classical music during at least a portion of thedelivery of a package to the customer.

The special events module 250 may determine special events associatedwith the customer (e.g., birthday, graduation, etc.) and/or generalspecial events, such as community events in a community of the customer.The special events module 250 may select sounds associated with thespecial events, which may be emitted by the UAV at one or more stages ofthe flight of the UAV to the destination 108. For example, the specialevents module 250 may determine that it is the customer's birthday, andmay select a birthday song to emit during a portion of the flight of theUAV. As another example, the special events module 250 may determinethat the day of delivery is a same day as an important sporting eventfavored by the customer, and the special events module 250 may select asound associated with the sporting event.

The order-specific sounds module 252 may select sounds based on thecontents of the order. For example, some commercial entities (e.g.,producers, suppliers, and/or manufacturers) of goods have jingles orother distinctive sounds that are associated with such entities. Theorder-specific sounds module 252 may select a sounds associated with acommercial entity. In various embodiments, the order-specific soundsmodule 252 may select sounds associated with actual items in thedelivery, such as songs from fixed-media music being delivered to thecustomer.

The sound assignment module 254 may assign the UAV 104 to load and/oremit selected sounds at certain times and/or during certain eventsduring the flight of the UAV 104 to/from the destination 108 associatedwith the customer 110. For example, the sound assignment module 254 maycause the UAV to load a birthday song to be played for the customer asthe UAV arrives at the destination 108. The sound assignment module 254may upload the sounds and/or rules for emitting the sounds to the UAV104 prior to deployment of the UAV 104 and/or during flight of the UAV(using a wireless network). The rules may be associated with differentstages of flight, different waypoints, and/or other triggers.

FIG. 3 is a perspective view of an illustrative propulsion system 300that includes one or more different sound masking devices. Thepropulsion system 300 includes an example of one of multiple possiblepropulsion systems used on a UAV, such as the UAV 104. For example, thepropulsion system 300 may include 4, 6, 8 or another number ofpropulsion units on a given UAV depending on a configuration of the UAV.

The propulsion system 300 may include a frame 302, a motor 304, apropeller 306, and a drive shaft 308 coupled to the motor 304 and thepropeller 306. The motor 304 may cause rotation of the drive shaft 308and the propeller 306 in response to power supplied by an electronicspeed control ESC. The propulsion system 300 may include one or more ofthe sound devices 214(M), which may cause emission of sound duringrotation of the drive shaft 308 and the propeller 306.

A first sound device 310 may include static features coupled to thepropeller 306. The static features may be dimples, cavities, cuts,edges, and/or other features that cause generation of sound when thepropeller rotates at given speeds. The first sound device 310 may beused to reduce sound generated from the propeller and/or modify thesound caused by the propeller to make the sound less annoying or less ofa nuisance to listeners (bystanders). In some embodiments, the firstsound device 310 may be integrally formed in the blades of thepropeller.

A second sound device 312 may be located proximate to ends of thepropeller 306 and coupled to the propeller 306. The second sound device312 may include features that cause emission of sound during rotation ofthe propeller caused by airflow, such as to create a whistle or similarsounds. For example, the second sound device may be implemented as aslide whistle. Unlike the first sound device 310, the second sounddevice 312 may include one or more actuators to cause change in thesound output or caused to be output by the second sound device 312. Theactuators may change an orientation of the second sound device 312and/or an orientation of a component of the second sound device (e.g., areed, a fin, an aperture, etc.). By controlling the actuators, via thesound device controller 226, the second sound device 312 may emit afluctuating sound, which may be more soothing and calming than a flatand constant sound or whistle. The sound device controller 226 may causemovement of the second sound device using predetermined controls, randomcontrols, or a combination of both to create sounds that maskconventional sounds generated by propellers and motors of a UAV. Thesecond sound device 312 may be coupled to all propellers, or selectedpropellers at both ends or at a single end.

A third sound device 314 may be coupled to the propeller 306 and/or thedrive shaft 308 and may rotate under control of the motor 304. The thirdsound device may include movable features 316, such as fins, reeds, orother components that may vary sound caused by airflow about the thirdsound device 314 during rotation. The moveable features 316 may open(expose more airflow across a noise-generating surface) and close(reduce or terminate airflow across the noise-generating surface). Thesound device controller 226 may control movement of the movablefeatures, which may be moved by actuators. In some embodiments, thethird sound device 314 may simulate playing of a harmonica byselectively directing airflow into different sound-making components ofthe third sound device 314. By controlling the actuators, via the sounddevice controller 226, the third sound device 314 may emit a fluctuatingsound, which may be more soothing and calming than a flat and constantsound or whistle. The sound device controller 226 may cause movement ofthe moveable features 316 of the sound device 314 using predeterminedcontrols, random controls, or a combination of both to create soundsthat mask conventional sounds generated by propellers and motors of aUAV. The second sound device 312 may be coupled to all propellers ordrive shafts, or selected propellers or drive shafts.

In some embodiments, the motors 304 may be configured to generatepredetermined sounds that mask conventional sounds caused by motors. Forexample, the motor 304 may include fins, reeds, and/or other featuresthat cause emission of sound during operation of the motor 304 atdifferent speeds, which may create sounds that mask conventional soundsgenerated by propellers and motors of a UAV. In some embodiments, anaudio signal may be overlaid with a pulse width modulation (PWM) signalused to control the motor 304. The audio signal may create arecognizable sound when the motor operates. This audio signal may beselected to mask at least part of the sound generated during normal orconventional operation of the motor (e.g., masking parts of sound notassociated with the audio signal).

FIGS. 4-9 are flow diagrams of illustrative processes. The processes areillustrated as a collection of blocks in a logical flow graph, whichrepresent a sequence of operations that can be implemented in hardware,software, or a combination thereof. In the context of software, theblocks represent computer-executable instructions stored on one or morecomputer-readable storage media that, when executed by one or moreprocessors, perform the recited operations. Generally,computer-executable instructions include routines, programs, objects,components, data structures, and the like that perform particularfunctions or implement particular abstract data types. The order inwhich the operations are described is not intended to be construed as alimitation, and any number of the described blocks can be combined inany order and/or in parallel to implement the processes. The processesdiscussed below may be combined in any way to create derivativeprocesses that are still within the scope of this disclosure.

FIG. 4 is a pictorial flow diagram of an illustrative process 400 toemit different sounds at different stages of flight by a UAV throughairspace 402. The process 400 is described with reference to theenvironment 100 and the architectures 200 and 240. The airspace 402 mayinclude the first threshold distance 116 from the location of deployment(e.g., from a fulfillment center or other location), the secondthreshold distance 124 from the destination 108, and the third thresholddistance from the destination 108.

At 404, the UAV 104 may emit a deployment sound, which may createawareness of the deployment. For example, the deployment sound maynotify workers in a fulfillment center or service center that the UAV104 is being deployed, powering up, and/or initiating flight.

The UAV 104 may gain altitude to a cruising airspace 406 between a firstaltitude 408 and a second altitude 410. At 412, while in the cruisingairspace 406, the UAV 104 may emit a transit sound. The transit soundmay be used to mask a conventional sound of the UAV. The transit soundmay be associated with a calming or shy sound that is not offensive andnot annoying. Examples of possible transit sounds may include sounds ofbirds, sounds of animals, sounds of water, wind sounds, sounds of calmtraffic, sound associated with a fictitious or real person, a cartooncharacter, or a robot, and/or other typical sounds associated with anthe environment in which the UAV flies that are not otherwise anuisance. The transit sounds may be updated as the UAV enters differentenvironments, such as when the UAV moves from an urban environment to arural environment, the transit sounds may change from a first transitsound to a second, different transit sound that is more closelyassociated with the environment in which the UAV operates. In someembodiments, emission of the transit sounds may be contingent on aproximity of people, such that no sound is emitted when the UAV is farfrom people that might hear the UAV.

The UAV 104 may lower altitude to an approach airspace 414 between thesecond altitude 410 and a third altitude 416. At 418, while in theapproach airspace 414 and/or within the second threshold distance 124,the UAV 104 may emit an approach sound. The approach sound may be usedto mask a conventional sound of the UAV. In some embodiments, theapproach sound may be similar to the transit sounds. However, theapproach sound may be different, and may be used to announce an arrivalof the UAV to the customer 110, to a location, and/or provide otherinformation. For example, the approach sound may be a sound associatedwith a specific UAV used to service a particular area (e.g., UAV “Bill”that delivers items to a first portion of a neighborhood, etc.). Theapproach sound may be a customer selected sound that enables thecustomer 110 to identify the UAV as delivering an item to the customer.In various embodiments, the approach sound may be associated with thecustomer, the contents of the delivery, and/or a special event, asdescribed above. The approach sound may be used to mask other soundsgenerated during operation of the UAV.

The UAV 104 may lower altitude below the third altitude 416. At 420,while below the third altitude and/or within the third thresholddistance 126 from the destination 108, such as when the UAV 104 is nearor over the destination and just before and/or during deposit of thepackage 106, the UAV 104 may emit a deposit sound. The deposit sound maybe used to mask a conventional sound of the UAV. In some embodiments,the deposit sound may be similar to the approach sound. However, thedeposit sound may be different, and may be used to announce a deposit ofthe package 106 by the UAV to the customer 110, to a location, and/orprovide other information. For example, the deposit sound may provideinstructions and/or a warning to bystanders about the imminent depositof the package at the destination 108. The deposit sound may be acustomer selected sound that enables the customer 110 to identify theUAV as delivering an item to the customer. In various embodiments, thedeposit sound may be associated with the customer, the contents of thedelivery, and/or a special event, as described above.

At 422, the UAV may emit a departing sound. The departing sound mayserve a similar function as the deploy sound at the operation 404, butmay be a different sound. Upon return to the fulfillment center orduring later flight, the UAV may also emit sounds, such those describedabove, possibly using similar triggers (e.g., zones, altitudes,airspaces, etc.) as discussed above.

FIG. 5 is a flow diagram of an illustrative process 500 to emittingmasking sounds during a delivery, some of the sounds possibly beingselected based on information associated with a customer of the item(s)in the delivery. The process 500 is described with reference to theenvironment 100 and the architectures 200 and 240.

At 502, the sound selection module 224, possibly using input from thelocation analysis module 228 and/or the navigation system 208, maydetermine a stage of flight of a UAV. The stage of flight may be any ofthe stages discussed with respect to the environment 100 and/or theprocess 400. The stages may include takeoff, cruising, approach,landing, package deposit, and/or other stages. In some embodiments,changes from one environment to another different environment beconsidered a change in stages, such as traveling at a cruising altitudefrom an urban environment to a rural environment or from a humanpopulated environment to a non-populated environment.

At 504, the sound selection module 224 may select a sound based on thedetermination at the operation 502. The sound selection module 224 mayapply rules that associate that stage of flight and/or other parameters,with sounds to be emitted by the UAV via the speaker 214(2) and/or thesound device 214(M). The selected sounds may not be customer specificsince the UAV is not yet near the destination associated with thecustomer.

At 506, the navigation system 208 may determine whether the UAV is neara destination, such as within the second threshold distance 124 orwithin the third threshold distance 126. When the UAV is not near thedestination (following the “no” route from the decision operation 506),then the process 500 may return to the operation 502 for continuedprocessing. When the UAV 104 is near the destination (following the“yes” route from the decision operation 506), then the process 500 mayadvance to an operation 508.

At 508, the sound selection module 224 may determine a sound to emit forthe customer. The sound may be preselected by the customer using thecustomer preference module 248 or selected based on information aboutthe customer. In some embodiments, the sound may be recognizable by thecustomer to enable the customer to identify the sound as meaning thatthe customer's package is nearby and will be delivered shortly.

At 510, the sound device controller 226 may cause the speakers 214(2)and/or the sound devices 214(M) to emit the sound selected at theoperation 508. At 512, the UAV may deposit the item at the destination.The UAV may continue to play the sound selected at the operation 508until an endpoint, which may be a threshold amount of time afterdepositing the package 106 at the destination 108 (including zerominutes).

FIG. 6 is a flow diagram of an illustrative process 600 to select customsounds for use during a delivery of a package by the UAV. The process600 is described with reference to the environment 100 and thearchitectures 200 and 240. The process may be performed by the centralcommand.

At 602, the customer preference module 248 may identify a customer toreceive a delivery. The customer may be identified based on an orderprocessed by the fulfillment center 102. The customer preference module248 may access the data 256, which may include information about thecustomer's preferences and/or other information associated with thecustomer. The data 256 may also include other information related toitems in an order for the customer (e.g., included in the package 106)and/or other information that may be used to select a sound to beemitted by the UAV during a delivery of the package to the customer.

At 604, the sound assignment module 254 may determine to select acustomer selected sound to be assigned to the UAV for emission duringthe delivery. When a customer selected sound is available and to be used(following the “yes” route from the decision operation 604), then theprocess 600 may advance to an operation 606 to assign the customerselected sound for use by the UAV during the delivery of the package 106to the customer. When the customer selected sound is not available ornot to be used (following the “no” route from the decision operation604), then the process 600 may advance to a decision operation 608.

At 608, the sound assignment module 254 may determine to select aspecial event sound to be assigned to the UAV for emission during thedelivery. A special event sound may be associated with an event that isimportant or otherwise of interest to the customer, such as a birthday,a sporting event, and/or other “event” or “special” sounds recognizableby the customer and/or bystanders that may hear the sound. When aspecial event sound is available and to be used (following the “yes”route from the decision operation 608), then the process 600 may advanceto an operation 610 to assign, via the special events module 250, thespecial event sound for use by the UAV during the delivery of thepackage 106 to the customer. When the special event sound is notavailable or not to be used (following the “no” route from the decisionoperation 608), then the process 600 may advance to a decision operation612.

At 612, the sound assignment module 254 may determine to select acommercial sound associated with a commercial entity to be assigned tothe UAV for emission during the delivery. The commercial sound may beassociated with an item in the package 106. For example, the commercialsound may be a jingle used by a manufacturer, producer, designer, orsupplier of an item in the package 106. When a commercial sound isavailable and to be used (following the “yes” route from the decisionoperation 612), then the process 600 may advance to an operation 614 toassign the commercial sound, via the order-specific sounds module 252,for use by the UAV during the delivery of the package 106 to thecustomer. When the commercial sound is not available or not to be used(following the “no” route from the decision operation 612), then theprocess 600 may advance to a decision operation 616.

At 616, the sound assignment module 254 may determine to select anauto-assigned sound to be assigned to the UAV for emission during thedelivery. The auto-assigned sound may be a sound that is assigned to thecustomer based on information about the customer, such as information ina customer profile that may indicate likes and dislikes of the customerpertaining to sounds. For example, the auto-assigned sound may beclassical music when the customer previously purchased classical musicto be delivered by a UAV or by other delivery mechanisms. When anauto-assigned sound is available for determination and to be used(following the “yes” route from the decision operation 612), then theprocess 600 may advance to an operation 618.

At 618, the customer preference module 248 may determine theauto-assigned sound for use by the UAV during the delivery of thepackage 106 to the customer, possibly using the data 256 that includesinformation about the customer. At 620, the auto-assigned sound may beassigned to the UAV for emission during the delivery.

When the auto-assigned sound is not available or not to be used(following the “no” route from the decision operation 616), then theprocess 600 may advance to an operation 622. At 622, the soundassignment module 254 may assign a default sound for use by the UAVduring the delivery of the package 106 to the customer. The defaultsound may mimic an environmental sound and/or otherwise be a soundassociated with calmness, animals or birds, and/or other non-threateningobjects while not being annoying, offensive, or a nuisance.

Following at one of the operations 606, 610, 614, 620, and 622, thesound assignment module 254 may upload the assigned sound to the UAV,possibly along with other sounds to be emitted by the UAV during theflight of the UAV to/from the destination. The sounds assigned at theoperations 606, 610, 614, 620, or 622 may be used at the approach stageor deposit stage of the delivery, such as pertaining to the operations418 and/or 420 described in the process 400.

FIG. 7 is a flow diagram of an illustrative process 700 to perform atleast partial noise-canceling during operation of the UAV. The process700 is described with reference to the environment 100 and thearchitectures 200 and 240.

At 702, the UAV may be deployed to fly to a destination to deposit apackage for a customer. The UAV may be deployed from a fulfillmentcenter, for example.

At 704, the location analysis module 228 may determine whether the UAVis within a threshold distance from people and/or from places thatpeople typically reside or congregate (e.g., from buildings, publicparks, beaches, etc.). The location analysis module 228 may base thisdetermination on an altitude of the UAV and/or on other factors. Thelocation analysis module 228 may determine the location based onpredetermined configurations, by analyzing imagery captured by imagingdevices on the UAV, and/or using other techniques. When the UAV is notwithin the threshold distance (following the “no” route from thedecision operation 704), then the process 700 may advance to anoperation 706. At 706, the sound device controller 226 may terminateoperation of any sound device (e.g., the speaker 214(2) and/or the sounddevices 214(M)), and then return to the decision operation 704.

When the UAV is within the threshold distance (following the “yes” routefrom the decision operation 704), then the process 700 may advance to anoperation 708. At 708, the noise canceling module 222 may perform noisecanceling using input from the microphone 214(1) and output by thespeaker(s) 214(2). The noise canceling module 222 may attempt to cancelall the noise generated by the propellers and/or motors of the UAV orportions of the sounds that are regarded or classified as annoying and anuisance to bystanders that can hear the noise.

At 708, the sound device controller 226 may cause the speaker(s) 214(2)and/or the sound devices 214(M) to emit sound while the noise cancelingmodule 222 causes at least some of the UAV noises to be canceled andwhile the UAV is within the threshold distance from people. Followingthe operation 708, the process 700 may return to the decision operation704 after a random or fixed amount of time has passed. By performing thedecision operation 704 and selectively terminating sound devices, theUAV 104 may conserve power resources.

FIG. 8 is a flow diagram of an illustrative process 800 to select soundsto emit based at least partly on attributes of a location of the UAV.The process 800 is described with reference to the environment 100 andthe architectures 200 and 240.

At 802, the location analysis module 228 and/or the navigation system208 may determine a location of the UAV 208 during a flight to adestination. The location by be a general area within airspace or overan area of land, such as over a city, over a forest, over a populatedarea, over a farm, etc.

At 804, the sound selection module 224 may determine whether a sound isassigned to the location determine at the operation 802. When a sound isassigned to the location (following the “yes” route from the decisionoperation 804), then the process 800 may advance to an operation 806. At806, the sound selection module 224 may assign the sound to be emitted,via the sound device controller 226, while the UAV flies over thelocation. Following the operation 806, the process 800 may return to theoperation 802 to update the location after a random or fixed amount oftime has passed, for example.

When a sound is not assigned to the location (following the “no” routefrom the decision operation 804), then the process 800 may advance to anoperation 808. At 808, the location analysis module 228 may obtaindescriptive attributes about the current location. The descriptiveattributes may be extracted from an analysis of imagery, such as todetermine whether the area include buildings, trees, people, animals,and/or other known objects.

At 810, the sound selection module 224 may select a sound based on theattributes determined at the operation 808. For example, if theattributes indicate that the current location is over a forest, thesound selection module 224 may cause the UAV to emit sounds commonlyhear in a forest. As another example, if the attributes indicate thatthe current location is over a city, the sound selection module 224 maycause the UAV to emit sounds commonly hear in the city or other soundsthat are soothing to people. As yet another example, if the attributesindicate that the current location is over a farm or rural area, thesound selection module 224 may cause the UAV to emit sounds commonlyhear in those respective areas, such as sounds of birds or other animalsor farm machines. At 812, the sound device controller 226 may cause theUAV, via the speaker(s) 214(2) and/or the sound devices 214(M), to emitthe sounds selected at the operation 810. Following the operation 812,the process 800 may return to the operation 802 to update the locationafter a random or fixed amount of time has passed, for example.

FIG. 9 is a flow diagram of an illustrative process 900 to test soundsand receive feedback from listeners enabling ranking of the sounds basedon the feedback. The process 900 is described with reference to theenvironment 100 and the architectures 200 and 240.

At 902, the sound assignment module 254 may determine a first sound usedat a particular stage of flight of the UAV at a first time. At 904, thesound assignment module 254 may determine a second sound used at theparticular stage of flight of the UAV at a second time, which may beduring a different flight for a different delivery. The particular stagefrom the first time and the second time may be similar or a same stageof flight.

At 906, the sound assignment module 254 may receive feedback frombystanders and/or other people who may be able to hear the first sound,the second sound, or both, and provide feedback usable to rank thesounds. The ranking may indicate a preference by the bystanders and/orother people for the first sound or the second sound.

At 908, the sound assignment module 254 may rank the first sound and/orthe second sound based on the feedback. The ranking may be a numericalranking, a binary ranking (use again, do not use again), and/or othertypes of rankings that may be used to determine future use and frequencyof the respective sounds. The process 900 may be used to test new soundsand/or test current sounds over time to ensure the sounds are found tobe pleasing to customer, who may have evolving tastes and preferencesregarding sounds, and in particular, regarding sounds emitted from UAVs.

Although the subject matter has been described in language specific tostructural features and/or methodological acts, it is to be understoodthat the subject matter defined in the appended claims is notnecessarily limited to the specific features or acts described. Rather,the specific features and acts are disclosed as illustrative forms ofimplementing the claims.

What is claimed is:
 1. A method comprising: determining a destinationfor delivery of a package by an unmanned aerial vehicle (UAV); causing aspeaker onboard the UAV to emit a first sound during at least a firstportion of the delivery to the destination, the first portioncorresponding to at least a cruising stage of flight; selecting a secondsound to be emitted by the speaker during at least a second portion ofthe delivery to the destination, the selecting the second sound based atleast in part on at least one of a user preference, contents of thepackage, or the destination and the second portion corresponding to atleast an approach or landing stage of flight; and causing the speaker toemit the second sound during at least the second portion.
 2. The methodas recited in claim 1, further comprising receiving a selection of thesecond sound from at least one of a customer associated with thedestination, a merchant that provides an item included in the package,or a supplier of the item included in the package.
 3. The method asrecited in claim 1, further comprising selecting the second sound basedat least in part on a prior sound association with a commercial entitythat is associated with at least one item included in the package. 4.The method as recited in claim 1 further comprising tracking a locationof the UAV to determine a stage of flight of the UAV, and whereinselecting the second sound is based at least in part on the stage offlight of the UAV.
 5. The method as recited in claim 1, wherein thefirst sound comprises a transit sound to mask a sound of the UAV.
 6. Themethod as recited in claim 1, further comprising accessing a transactionhistory of a customer associated with the delivery or customer accountinformation associated with the customer, and wherein selecting thesecond sound is based at least in part on the transaction history of thecustomer or the customer account information.
 7. The method as recitedin claim 1, further comprising: determining that the UAV is currentlylocated over a particular environment; and selecting a third sound basedat least in part on a predetermined association between the sound andthe particular environment.
 8. The method as recited in claim 1 furthercomprising: receiving input sound signals from a microphone based atleast in part on a noise generated from operation of the UAV; generatinginverted sound signals based at least in part on the input soundsignals, the inverted sound signals to cancel at least part of the noisegenerated from the operation of the UAV; and causing the speaker to emita third sound based at least in part on the inverted sound signals. 9.An unmanned aerial vehicle (UAV) comprising: a speaker; one or moreprocessors; and memory storing computer-executable instructions that,when executed, cause the one or more processors to: track a location ofthe UAV during a flight to deliver a package to a destination associatedwith a customer; cause the speaker to emit a first sound during at leasta first portion of the flight, the first portion corresponding to atleast a cruising stage of the flight; access data associated with asecond sound to be emitted by the speaker, the second sound associatedwith at least one of a commercial entity or a preference of thecustomer; determine that the UAV is executing a second portion of theflight, the second portion corresponding to at least a flight approachstage of the flight; and cause the speaker to emit the second soundduring at least the flight approach stage of the flight.
 10. The UAV asrecited in claim 9, wherein determine that the UAV is executing a secondportion of the flight includes determining that the UAV is within athreshold distance from the destination and causing the speaker to emitthe second sound in response to determining that the UAV is within thethreshold distance from the destination.
 11. The UAV as recited in claim9, wherein the second sound mimics at least one of a sound associatedwith a living being or a sound associated with a natural environment.12. The UAV as recited in claim 9, wherein the computer-executableinstructions further cause the one or more processors to cause thespeaker to emit a third sound during a third portion of the flight, thedifferent sound selected based at least in part on a location of theUAV.
 13. The UAV as recited in claim 9, further comprising at least onesound device coupled to a propeller or a shaft that couples a motor tothe propeller, the at least one sound device to cause the UAV to emit atleast one of the first sound or the second sound.
 14. The UAV as recitedin claim 9, wherein the computer-executable instructions further causethe one or more processors to upload the second sound from a profileassociated with the customer, the sound being identifiable by thecustomer to inform the customer that arrival of the package is imminent.15. The UAV as recited in claim 9, wherein the computer-executableinstructions further cause the one or more processors to determine analtitude of the UAV, and wherein cause the speaker to emit the secondsound is based at least in part on the altitude being less than athreshold altitude.
 16. A system comprising: one or more processors; andmemory storing computer-executable instructions that, when executed,cause the one or more processors to: determine a destination fordelivery of a package by an unmanned aerial vehicle (UAV); cause aspeaker onboard the UAV to emit a first sound during at least a firstportion of a flight to the destination, the first portion correspondingto at least a cruising stage of the flight; select a second sound to beemitted by the speaker during at least a second portion of the flight tothe destination, the second portion corresponding to at least anapproach or landing stage of the flight; and upload the second sound tothe UAV for playback by the speaker during at least the second portionof the flight.
 17. The system as recited in claim 16, wherein thepackage is associated with a customer, and wherein select the secondsound is based at least in part on a preference or attribute associatedwith the customer.
 18. The system as recited in claim 16, wherein thesecond sound mimics at least one of a sound associated with an animal, abird, a fictitious or real person, a cartoon character, a robot, or asound associated with weather.
 19. The system as recited in claim 16,wherein the second sound is selected based at least in part on a profileassociated with a customer to receive the package.
 20. The system asrecited in claim 16, wherein the computer-executable instructions causethe one or more processors to upload the second sound from a profileassociated with the customer.